Samantha Leigh, a UC Irvine researcher with the department of ecology and evolutionary biology and lead author of the study, said she grew interested in the bonnethead's diet after reading a 2007 study on how the species eats lots of grass.
Scientists at the University of California in Irvine, and Florida International University in Miami, chose to investigate the sharks' dietary habits after reading reports of the fish chomping on seagrass, the flowering marine plant that forms subsea meadows in some coastal waters. What an animal consumes is not necessarily the same as what it digests and retains nutrients from.
The bonnethead shark is abundant in the shallow waters of the eastern Pacific, the Western Atlantic, and the Gulf of Mexico, where they feed on crab, shrimp, snails and bony fish.
The researchers then fed the bonnetheads a diet made up of 90% seagrass and 10% squid. They also showed the fish digested the seagrass using enzymes that broke down the plants, like starch and cellulose, since their razor-sharp teeth aren't well suited for chewing. The "ecological implications" of 4.9 million bonnethead sharks munching on seagrass are not yet fully understood.
"Given that bonnetheads have a digestive system that resembles that of closely-related species that we know to be strict carnivores, we need to re-think what it means to have a 'carnivorous gut, '" Leigh told Fox.More news: British Airways investigating data breach from 380000 card payments
The results of the study suggested that sharks have the same enzymes that help us break down plant material and that they were digesting the grass.
As it turned out, not always the sharks are bloodthirsty predators, some carnivorous creatures eat sea plants. The National Aquarium states that the sharks typically grow to a length of 30 to 48 inches and weight of up to 24 pounds.
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It was uncertain whether the sharks were actually feeding on the seagrass or just accidentally eating the vegetation while hunting for other prey.More news: Philippines mayor shot dead inside his office
Hold on to your bonnets for this one, as the world's first plant-eating shark has just been discovered and its name is the bonnethead shark.
The coastal bonnethead shark, a smaller relative of the hammerhead, is thought to be the first known omnivorous shark.
In fact, seagrass meadows are the most widespread coastal ecosystems on Earth, providing a home for thousands of fish and invertebrates, while at the same time filtering water and absorbing excess carbon dioxide from the atmosphere.
At the moment, there are few suspicions that other shark species have broadened their diets to consume plants as well as meat.More news: Samsung: Time for folding smartphones